The differential diagnosis of small intestinal infections is broad, making the identification and management of these disorders challenging. The majority of cases of acute diarrhea are self-limited and do not require diagnostic evaluation or treatment. Most patients do not require specific therapy, and treatment should focus on fluid and electrolyte replacement. In patients with severe, persistent, or chronic diarrhea, a careful medical history and routine stool testing are helpful in determining the cause. Pathogen-specific therapy should be given in patients in whom a pathogen is identified. In those without an identifiable pathogen, antidiarrheal agents are helpful in reducing the number of bowel movements and preventing further dehydration. Endoscopy may be helpful in patients with severe diarrhea and a negative stool evaluation, particularly in HIV-infected patients with chronic diarrhea. Surgery has a limited role in the management of small intestinal infections, but may be lifesaving in patients with intestinal perforation or small bowel obstruction.